1. Field of the Invention
The present invention relates to a method of preparing DVD-Video formatted data, preferably of a movie, for transmission from a server to a client, wherein the DVD-Video formatted data are provided as a set of predetermined data files. The present invention also relates to a method used in a DVD-apparatus for reconstructing DVD-Video data prepared according to the afore-mentioned method. Further, the invention relates to a DVD-Video data structure comprising a set of data files containing video, audio and rich content data and organized according to the DVD-Video specification. Further, the invention relates to a record carrier for use in a DVD-player and a DVD-apparatus for playing video films stored on a record carrier, comprising reading means for reading data stored on said record carrier, means for processing DVD-Video formatted files and decoding means for decoding e.g. mpeg-4 encoded data. Finally, the invention relates to a computer program product and a computer program including hardware and software for consumer electronic devices.
2. Description of the Related Art
In the past, offering and buying of digital content, like music (mp3 music stores, for example) became more and more popular and has developed to a considerable business. This growth of business was supported by an increase in bandwidth of Internet connections allowing to download digital content in shorter times on the one hand side, and the development of simple and easy to use players for playing the downloaded content on the other hand side. However, the still limited bandwidth of Internet connections has prevented a further growth of content distribution over the Internet with respect to video content, e.g. the distribution of video content is still carried out in the form of DVD media on which the video content is stored in correspondence with the DVD-Video specification.
As it is known in the art, the DVD-Video format allows to incorporate rich content, meaning sub-picture data, like subtitles, etc., navigation information, etc.
Commonly, the video and audio data is encoded according to the mpeg-2 or mpeg-1 standard and encapsulated in data packets which are part of the DVD-Video formatted data structure.
Due to the fact that the available Internet bandwidths increase continuously with a reduction of costs, downloading of videos, movies, etc. is becoming more popular. However, simple downloading of mpeg-2 encoded or mpeg-4 encoded video streams is not desired, since the user would in this case need special software to bring the mpeg-2/4 data stream into the DVD-Video format necessary for producing a DVD-Video disc.
For example, there is a need for a simple and easy to use solution for downloading DVD-Video formatted video content. Additionally, it is desirable to be able to store a DVD on a CD or on a hard disk, when one has for example the wish to store an originally bought DVD in a safe place and to only use a copy of the DVD.
While the DVD format has a directory structure having certain files in a video-title set (Video_TS) directory, and the actual video or audio content is included in video object files (VOB-Extension File), and the actual video content is again preceded by pack headers and PES packet headers, there exist other formats requiring video data to be written without any interspersed control information.
Such a file format is the MPEG-4 file format as defined in the international standard ISO/IEC 14496-1:2002. Particularly, section 13 “file format” of part 1 “systems” of this MPEG-4 standard is of particular relevance. Here, the audio or video data are required to be written into a so-called “mdat” atom. The MPEG-4 standard requires that the data in this mdat atom is data in so-called chunks, i.e., data which only represent payload data constituting an audio or video or, generally, a media content without any packet control information there between. Stated in other words, an MPEG-4 conforming decoder which is also called a “legacy” decoder in this document assumes that the mdat atom only includes group of picture chunks, i.e., a video-encoded group of picture data relating to subsequent groups of pictures. One exception provided for by MPEG-4 is that an mdat atom can include several tracks, which means that one can include for example several movies into a single MPEG-4 container. When the MPEG-4 player is to play the first movie or the first track, then a correct starting point in the mdat atom is searched for (this starting point can be an address or a certain sector boundary on a storage medium), and the data starting at this starting point and immediately subsequent data are decoded until all data of this chunk is completely decoded.
In contrast thereto, as stated above, the MPEG-2 file format, which is the DVD file format is different from this MPEG-4 file philosophy, since there exist several files, where each file includes control information, and since, within a single file, groups of picture data are not written subsequently but a group is normally preceded by certain headers including control information. Therefore, on a regular DVD, the data is not written in chunks, but is packed in so-called PES packets (PES=Program Elementary Stream).
Furthermore, because of the DVD file size restriction, video objects can be separated into two or even more video object files. It ist to be noted in this context that a title set includes titles having the same attributes such as an aspect ratio. When a movie in 16:9 is to be written on the DVD, and when a makeof in 4:3 is to be written on the DVD, then two title sets for the DVD have to be generated.
In the meantime, DVD players have become more and more popular. This means that there exist many home or professional users possessing a DVD player connected to a television set. Thus, the regular user is accustomed to her or his DVD/television set combination.
As stated before, increasing the available internet bandwidth allows to distribute movies not only via DVDs, which can be sold in a certain store, but also allow to download a complete movie against a fee paid by the movie recipient. However, the DVD format requiring several separate files is not very well suited for a comfort download via the internet. Instead, a simple to use and comfortable procedure is required, which allows the complete order and deliverance of any file format from the internet using a single click of the user.
Furthermore, an error-free and safe download can better be guaranteed for the user, which cannot be guaranteed in all cases, when a single data entity instead of several different data entities has to be downloaded via the Internet or any other net such as a wireless net.
Furthermore, as outlined above, it is a disadvantage, when additional steps by the user are required to reconstruct a file structure of a DVD disc in order to feed the internet-downloaded data into a DVD player separate from the computer, i.e., connected to the television set.